Conventionally, for this type of display devices, configurations as disclosed in Patent Documents 1 to 3 have been proposed.
In a conventional configuration described in Patent Document 1, a plurality of panel switches are arranged around a liquid crystal panel, and a light guide lens is arranged between the liquid crystal panel and the panel switches. Light from the liquid crystal panel is guided to the panel switches via the light guide lens to illuminate the panel switches. Thus, in Patent Document 1, a light source dedicated to illuminate the panel switches is not required.
In a conventional configuration described in Patent Document 2, a light control means is provided between a plurality of light sources for vehicle speed display and a plurality of light sources for a shift range display. The light control means allows light from the light sources for vehicle speed display to be radiated to a shift range display, which serves as backlight for the shift range display. In contrast, light from the light sources for the shift range display is prevented from being radiated to the vehicle speed display, thereby preventing illumination unevenness in the vehicle speed display.
In a conventional configuration described in Patent Document 3, a front surface of a light shielding case having a meter therein is coated with a transparent case. A corner portion between a front wall portion and a side wall portion of the transparent case has a reflection portion for reflecting external light (light of a head lamp) entering from an edge of the side wall portion outward without allowing the light to pass to the front wall portion. This reflection portion shields the external light entering the light shielding case through the transparent case, thereby suppressing illumination unevenness in a meter display.
In a conventional configuration described in Patent Document 4, light from a light source is reflected on two reflection portions through an air layer to allow a front panel of a meter to perform surface-emitting. With this configuration, since an illumination chamber formed of an air layer can be formed, the whole of the front panel can be illuminated without using any planar illuminant, achieving cost reduction.
In the conventional configuration described in Patent Document 5, a reflecting mirror is provided at the rotational center of an indicator of a tachometer, and display light indicating vehicle travelling speed is emitted from a display to the reflecting mirror through a smoke glass so that the driver can see the travelling speed from display reflected by reflected light. With this configuration, since there is no need to provide a smoke glass in front of the meter, visibility of the tachometer indicator is ensured.    Patent Document 1: Japanese Laid-Open Patent Publication No. 2006-59565    Patent Document 2: Japanese Laid-Open Patent Publication No. 2006-145334    Patent Document 3: Japanese Laid-Open Patent Publication No. 2000-16118    Patent Document 4: Japanese Laid-Open Patent Publication No. 2001-281007    Patent Document 5: Japanese Laid-Open Patent Publication No. 2005-233276
However, each of the conventional configurations has the following problems.
In the configuration described in Patent Document 1, the whole of the panel switches is illuminated by light from the liquid crystal panel. Illumination of the panel switches in Patent Document 1 utilizes light of a liquid crystal display screen. Accordingly, the light amount of the switches depends on the light amount of the backlight for the liquid crystal screen to display the switches. Thus, when it is attempted to increase the light amount of the switches, the liquid crystal display screen becomes too bright. Accordingly, in the case of adopting this configuration for decorative illumination, it is difficult to obtain a desired decorative design due to limitations by brightness of the liquid crystal display screen or the like. Moreover, in the configuration described in Patent Document 1, an area for ensuring switch light is required in the liquid crystal screen, resulting in an increase in the whole of the liquid crystal display device in size. Further, in the case where this configuration is adopted to perform decorative illumination away from the liquid crystal screen, a long light guide lens is needed, and it is difficult to incorporate such a light guide lens in the limited space in the display device.
In the configuration described in Patent Document 2, the whole of the shift range display is illuminated by light from the light sources for vehicle speed display, which is effective in preventing illumination unevenness. However, it is difficult to satisfactorily display the vehicle speed and supply decorative illumination at the same time. Moreover, in the configuration described in Patent Document 2, the light control means for controlling light is needed to be provided between the plurality of light sources for vehicle speed display and the plurality of light sources for the shift range display, which makes the configuration complicated.
In the configuration described in Patent Document 3, the transparent case is provided with the reflection portion for shielding external light. That is, the configuration in Patent Document 3 serves to prevent light from entering into the case, not to utilize light, and therefore, the decorative effect of illumination cannot be expected.
In the configuration described in Patent Document 4, the reflection portion (in this embodiment, the prism-like portion) dedicated to guide light from the light source to the front panel of the meter is required. Despite the fact that cost reduction can be achieved, the number of components increases and the configuration becomes complicated. Moreover, in the configuration described in Patent Document 4, in the case of performing a decorative function, decorative and display functions need to be satisfied at the same time and thus, as described above, a desired decorative design cannot be ensured.
In the configuration described in Patent Document 5, since it is needed to provide the dedicated large and expensive reflecting mirror at the rotational center of the indicator of the tachometer, the number of components increases and moreover, unless the reflection angle of the reflecting mirror is accurately set, the display screen may be distorted. For this reason, the configuration described in Patent Document 5 inevitably leads to high costs. Also in the configuration described in Patent Document 5, in the case of performing a decorative function, decorative and display functions need to be satisfied at the same time and thus, as described above, a desired decorative design cannot be ensured.
The present invention is made in consideration of the problems in such conventional techniques. An objective of the present invention is to provide a display device capable of effectively achieving a decorative effect by utilizing a portion of a color filter at the front of a light-emitting display unit with a simple configuration, and a meter device using the display device.